2023届高考英语复习 情态动词学案

情态动词 I定义 情态动词(Modal Verbs) 表示说话人的态度、看法等。在意义，它们自身都有一定的词义；在形式上，不受任何人称、性、数变化的影响；在用法上，都不能独立充当谓语，只能和行为动词或系动词一起构成谓语。常见的情态动词有：can, could; may, might; must, have to; dare, need, shall, will, should, ought to, would, be able to等。 II 情态动词的基本用法 1 can, could的用法 （1）表“能力”常指体力、技能等产生的能力 eg. 1 He can play the piano quite well now. 2 Tom could swim when he was five. (2) 表“请求、许可”（多用于口语中） eg. 1 ---Can I go now? ---- Yes, you can. 2 You can’t eat your sandwiches here. 3 ---Could I borrow your book? ---- Yes, you can. /No, I’m afraid not. 注意：表“许可”时，could 和can 没有时间上的差异，只是语气上的区别。could 比can的语气更委婉、客气。could只用于疑问句，不用于肯定句，在回答时只用can. (3) 表客观上的可能性，也就是表示某人或某物一时的特点，可译为“有可能、有时会”。 eg. 1 Monkeys can be naughty. 2 He could be proud sometimes. 3 The weather there can be extremely hot. (4) 表推测，常用于否定、疑问句中。（could 比can的可能性小） eg. 1 Can’t it be true? 2 He can’t be in Beijing now. 3 At that time, I thought the story could be true. 4 He can’t have been at home last night, for the light wasn’t on. 5 Tom can’t be doing his homework in the classroom. (5) 表惊讶（常用于疑问句）can 的用法 eg. 1 How can you believe such a liar like him? 2 How can you be so careless！ 注意：be able to 表能力时可以与can 互换，但在将来和完成时必须用be able to 结构；表经过努力而成功地办到了某个具体的事时只用be able to (相当于succeed in doing 或manage to do)。 eg. 1 Can you type?/Are you able to type? 2 I’m sure we shall be able to get you a job soon. 3 He has been able to finish the work on time. 4 Because he worked hard he was able to pass the exam. can的习惯用法 1 can not but 不得不 eg I can not but admire his courage. 2 can not (couldn’t ) help doing 情不自禁 eg. When I heard what the little girl said I couldn’t help laughing. 3 can not… too… 怎么也不过分；越--- 越好 eg. 1 You can not too careful when you cross the street. 2 We can not praise him too much. 2 may, might 的用法 （1）表“许可、允许”常可译为“可以”might不表时态上的差异而是语气上比may更委婉，客气。 eg. 1 You may take this if you like. 2 Might I ask a question? （2）表推测（疑问句不用于此意）might 比may的可能性弱 eg. 1 He may be very busy now. 2 It may rain t